Process for the treatment of silver-nickel-cobalt-arsenic ores.



. the larger CAMILLO C. CITO, IRVING-TON, NEW JERSEY.

PROCESS FOR THE TREATMENT OF SILVER-NICKEL-COIiALT-ARSENIC ORES.

9419,05d. no Drawing.

To all whom it may concern: I

Be it known that I, CAMILLo C. Crro, a

subject of the Grand Duke of Luxemburg,

residing at Irvington, in the county of BS- 1 sex'and State of New Jersey, have invented a certain new and useful Improvement in Processes for the Treatment of Silver- Nickel-Cobalt-Arsenlc Ores, of which .the

following is a specification.

The. invention relates to the treatment of- Canadian or other ores which contain, besides silver, considerable quantities of nickel, cobalts, and especially arsenic. Generally, such ores run as follows: silver 800 to 10,000 ounces to the ton; nickel and cobalt 10 to arsenic 5 to lead none. 1

-The invention consists in the process and subrocesses hereinafter more particularly set orth,- whereby throu h electrolysis of an anode of the alloy produced by smelting said ore in thepresen'ce of copper, the metals are separated, so that alLof the silver may be recovered as a high grade product from the slimes, all of the nickel and cobaltis dissolved in the electrolyte together with copper is deposited in substantially pure to a certain number of ounces state on the cathode.

In carrying out my process I proceed as follows: The ore smelted in a reverberatory furnace without any preliminary treatment, such asroasting, etc. I add to said ore a percentage of copper, preferably equal to two thirds that of thenickel and cobalt and at least the same as that of the arsenic, and not less .in amount than the silver. Thus I may put in 20 per cent. of'copper,

,but if there is 25 per cent. of arsenic present,

the copper percentage should be increased .to 25 per cent. If the silver present amounts per ton, the amount of copper should not be less. lBesides the copper the necessary quantity of usual fluxes is to be added. By this smelting operation is produced an'ialloy containingp besides copper, all'the silver, nickel and cobalt and nearly all the arsenic in the ore treated. This is tapped from the furnace into molds of suitable shape to produce anodes for the electrolytic operation which next follows.

In the electrolytic bath, the cathodes are to be sheets of pure copper. The electrolyte is a solution of cop er sulfate in water, and during the whole e ectrolytic operation the solution should contain at least ten Specification of Letters Patent.

Application filed October13, 1909. Serial No. 522,475.

part of the arsenic, and all of the Patented Feb. is, into.

uric acid per liter. The density of the' electric current is to be regulated according to the composition of the anode and of the electrolyte. If the anode alloy varies in percentage of. silver and arsenic, the density of the current should correspondingly vary. The density will be increased proportionately to the quantity of copper in the electrolyte; The temperature of the bath is preferably to be about degrees centigrade; but is regulated by the percentage of arsenic in the anode. The higher this percentage, the higher should, be the temperature so as tobring as much of the ar-' senic is possible into the solution. 7

The result of the'electrolysis is practi-- cally lows:

1. Silver. All in the anode is precipitated in the'slimes.

2. Nickel-cobalt. All in the, anode remains quantitatively dissolved in the electrolyte.

quantitatively 3. Arsenic. The largest part of that in the anode remains dissolved in the electrolyte, the balance going into the slimes with the silver.

4. Copper. All in the anode is deposited in the form of pure electrolytic copper on. the cathode. A determination of this has yielded 99.98% Cu. Or, in other words,'the copper originally added as'a dlux is recovered as a commercial product.

And it is further to be noted that no gases which, on account of the arsenic, would be very dangerous, are developed during the electrolysis.

To state the result of the process in another wayI have distributed the metals of the anode respectively in diflerent places in the bath. On the cathode, is all the copper. In the slimes is all the silver and a small portion of the arsenic. In the electrolyte is all the nickel and cobalt and the greater part of the arsenic. As a consequence. of this distribution, the further treatment of the products is very simple.

Treatment 0 the sZimes.-These are rich or poor, accor( ing to the percentage of silver in the anode, but under all circumstances. they contain all the silver, since no traces of that metal ap ear either in the cathode or electrolyte. T e small amount of arsenic which enters the slimes, together with the silver, can easily be removed by a light roasting or a dissolving process. Thus, an ore orlginally contammgGOO 02s. of silver per ton, 19% arsenic, and'17.5% nlckel-cobalt, yielded slimes of 12,000 ozs. silver per ton; While the slimes of another orv that ran 3,500 ozs. of silver per ton contained 24,500

' trolyte containing the Whole of the nickelcobalt and the larger part of the arsenic can be brought up to the follow ng concentrations: silver none; copper 10 grams per liter; nickel-cobalt 55 grams per liter;

arsenic 30 grams per liter. From this solution, the larger part of the copper can be precipitated by the electric current, using a carbon anode. The remainder of the copper is :ulvantageously precipitated by H S' in the'cold, whereby very little sulfid of arsenic is formed. This copper product can be used over as a flux. All the arsenic can then be precipitated by H S in the heat, as sulfid of arsenic, which can be placed on the market as such. Nickel and cobalt can now be recovered, together or separate, by any of the methods usually e1nployedeither by electrolysis or by chemical precipitation. 4

Particular attention is now called to the following facts resulting from my aforesaid process. 1. I obtain a direct output of the principal metals. limiting,'at the same time, the forming of by-products. 2. From a complex anode, I deposit pure copper on the cathode. 3. The metals are extracted and deposited from the anode and not from the electrolyte. 4. The operation is exceedingly simple, and hence involves very low running expenses; 5. The most important metals are brought out with great rapidity: especially the silver which is recovered as a high grade product which, without difficulty, can be refined by any known process. 6. Despite the possible large amount of arsenic present,

danger from arsenious gases is practically elimlnated. 7. The copper added as flux is regained in the electrolytic operation as a commercial product. 8. By reason of the distribution of metals and of the quantitative deposit of all the silver in the slimes, I do not produce a plurality of different products, each containing more or less silver and each requiring separate treatment for its removal In another application for Letters Patent Serial No. 522,476 filed by me simultaneously herewith, I have described and claimed the process of smelting silver-nickel-cobaltarsenic ore, free from lead, in the presence of copper, which smelting process forms a step in mypresent process, and therefore, I do not claim said smelting process herein.

I claim:

1. The process of treating a silver-nickelcobalt-arsenic ore free from lead, which consists in first, smelting the ore in the presence cobalt and nearly all the arsenic, and second,

separating the metals by electrolysis from an anode of said alloy in an electrolyte containing copper sulfate.

In testimony whereof I have afiixed my signature in presence of two witnesses.

CAMILLO o. crro.

\Vitnesses Gnu'rnuon T. PORTER, MAY T. MGGARRY.

of copper to produce. an alloy containing 

